U.S. patent number 3,708,042 [Application Number 05/074,054] was granted by the patent office on 1973-01-02 for carbon core segmented friction disc.
This patent grant is currently assigned to The Bendix Corporation. Invention is credited to Walter J. Krause, Gilbert T. Stout.
United States Patent |
3,708,042 |
Krause , et al. |
January 2, 1973 |
CARBON CORE SEGMENTED FRICTION DISC
Abstract
A friction disc for a disc brake having a plurality of
interleaved brake rotor and stator discs which are forced together
to provide a friction effect. The rotor is provided with a
plurality of segments each of which includes a carbon block having
friction material pads fixedly secured to opposite faces thereof.
The segments are attached to a ring or strap which holds the
segments in fixed spaced-apart relationship to define an annular
rotor disc.
Inventors: |
Krause; Walter J. (South Bend,
IN), Stout; Gilbert T. (South Bend, IN) |
Assignee: |
The Bendix Corporation
(N/A)
|
Family
ID: |
22117419 |
Appl.
No.: |
05/074,054 |
Filed: |
September 21, 1970 |
Current U.S.
Class: |
188/73.2;
192/107R; 188/218XL |
Current CPC
Class: |
F16D
55/36 (20130101); F16D 2055/0058 (20130101) |
Current International
Class: |
F16D
55/36 (20060101); F16D 55/24 (20060101); F16D
55/00 (20060101); F16d 065/12 () |
Field of
Search: |
;188/73.2,218XL,264CE
;192/17R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Halvosa; George E. A.
Claims
We claim:
1. A friction disc for a disc type brake, said friction disc
comprising:
a torque transmitting ring member defined by alternate arcuate
first and second sections said first section being a flat metal
link provided with a pair of arcuately spaced apart openings at
each end thereof and said second section being two parallel spaced
apart flat metal links each of which are provided with a pair of
arcuately spaced apart openings at each end thereof;
said first section having opposite ends thereof interposed between
the adjacent ends of said alternate second sections with the
respective openings thereof in alignment;
first fastening means extending through one set of said aligned
openings to fixedly secure said first and second sections
together;
a plurality of circumferentially spaced apart arcuate friction disc
segments arranged end-to-end to form a substantially continuous
annular friction member;
said friction disc segments each having first and second cup
members containing friction material fixedly secured thereto each
of which cup members are provided with radially extending arcuately
spaced first and second lug portions;
a carbon block interposed between said first and second cup members
for maintaining the same in spaced apart relationship;
second fastening means extending through said first and second cup
members and said carbon block for holding the same in fixed
relative portions;
said first lug portions of said first and second cup members being
provided with openings therein for alignment with the remaining
openings in one end of said first section and associated aligned
openings of said second section;
said second lug portions of said first and second cup members being
provided with openings therein for alignment with the remaining
openings in the opposite end of said first section and associated
aligned openings of said second section; and
third fastening means extending through said openings in said first
and second lug portions and associated aligned openings of said
first and second sections to fixedly secure said friction disc
segment to said ring member and maintain said first and second
sections in fixed relative positions.
2. A friction disc as claimed in claim 1. wherein:
said first and second lug portions extend radially outwardly from
said cup members into engagement with said ring member thereby
positioning said cup members and attached carbon block radially
inwardly from said ring member.
3. A friction disc as claimed in claim 1. wherein said disc brake
is provided with at least one rotor member and wherein:
said rotor member is defined by said friction disc.
4. A friction disc as claimed in claim 1. wherein:
said second fastening means includes a rivet member extending
through the center portion of said carbon block.
5. A friction disc as claimed in claim 1. wherein said disc brake
is provided with at least one rotor member interposed between two
stator members engageable with said rotor member and wherein:
said rotor member is defined by said friction disc;
said stator members being arranged concentric with said rotor
member and each having an annular layer of friction material
fixedly secured thereto; and
actuating means operatively connected to said rotor and stator
members for forcing the same into engagement to establish
frictional engagement therebetween.
6. A friction disc as claimed in claim 5. wherein:
said carbon blocks are subjected to compression only in response to
frictional engagement of said rotor and stator members.
7. A friction disc as claimed in claim 1 wherein the disc type
brake is adapted for use with a rotatable wheel and wherein:
said two parallel spaced apart flat metal links are recessed at the
radially outermost portion thereof to accommodate an axially
extending drive key fixedly secured to said wheel.
8. A friction disc as claimed in claim 7 wherein:
said recessed radially outermost portion is in alignment with a
radial line extending between adjacent friction disc segments.
Description
BACKGROUND OF THE INVENTION
Disc brakes having a plurality of interleaved annular brake rotor
and stator elements are well known particularly in the field of
aircraft brakes as evidenced by U. S. Pat. No. 3,376,960 issued
Apr. 9, 1968 and U.S. Pat. No. 3,473,635 issued July 7, 1959. Such
prior art disc brakes teach a segmented rotor similar to that of
the present invention to the extent of providing a plurality of
segments each of which has a heat sink core defined by a material
having the desirable characteristics of high specific heat, low
density and high thermal conductivity. However, such segmented
rotors utilizing heat sink core material are not entirely
satisfactory for one or more reasons including structural
limitations peculiar to the core material, deterioration of the
core material into harmful oxide toxic to humans and core material
expense.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a carbon core
segmented rotor having the desirable characteristics of light
weight, structural simplicity, high heat sink capacity and
structural strength.
It is another object of the present invention to provide a carbon
core segmented friction disc which is reliable in operation and
relatively economical to manufacture by virtue of structural
simplicity.
It is an important object of the present invention to provide a
segmented rotor for a disc brake wherein the segments thereof are
provided with a carbon block sandwiched between layers of friction
material.
Other objects and advantages of the present invention will be
apparent from the following description taken with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents a sectional view of a symmetrical wheel and brake
assembly having an axis x-x and embodying the present
invention.
FIG. 2 represents a plan view of a portion of an annular rotor
embodying the present invention and shown removed from the wheel
and brake assembly of FIG. 1.
FIG. 3 represents a sectional view taken on line 3--3 of FIG.
2.
FIG. 4 represents a sectional view taken on line 4--4 of FIG.
2.
FIG. 5 represents a sectional view taken on line 5--5 of FIG.
2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, in particular, numeral 20 designates a wheel
rotatably mounted on a fixed axle 22 for rotation about axis x-- x.
A fixed brake carrier member 24 rigidly secured to axle 22 by any
suitable fastening means, not shown, is adapted to house a
plurality of circumferentially spaced apart, fluid actuated, brake
applying pistons 26 only one of which is shown. The pistons 26 are
slidably carried in cylinders 28 threadedly secured to carrier 24
each piston 26 being provided with a block of heat insulating
material 29 fastened thereto via a screw member 30. The pistons 26
are actuated upon demand by pressurized fluid controlled by control
means, not shown.
An annular pressure plate 32 suitably secured to pistons 26 is
actuated axially in response to pressurization of pistons 26 to
apply the brake. A torque tube 34 is provided with an axially
extending sleeve portion 36 integral with a radially extending
annular backing plate 38. A plurality of bolts 40 extend through
carrier member 24 into threaded engagement with sleeve portion
spaced to thereby fixedly secure the torque tube 34 to carrier
member 24.
The wheel 20 is formed of two sections, only one of which 42 is
shown, bolted together by a plurality of fastening means such as
bolts 44. A wheel rim 46 and wheel hub 48 are connected via
integral wheel spokes 50.
A plurality of annular brake rotors 52 are spaced apart axially by
brake stators 54 interposed therebetween. The rotors 52 are
slidably keyed for axial movement to a retaining member 56 which,
in turn, is suitably secured to wheel rim 46 and rotated by wheel
20. The stators 54 are slidably keyed for axial movement to sleeve
portion 36 which prevents rotational movement of stators 54.
The rotors 52 are provided with facings of friction material. The
interleaved rotors 52 and stators 54 are compressed between
pressure plate 32 and backing plate 38 in response to
pressurization of pistons 26 thereby creating frictional engagement
between the rotors 52 and stators 54 to retard rotation of wheel 20
relative to axle 22.
Referring to FIGS. 2, 3, 4 and 5, each of the rotors 52 is defined
by a plurality of segments 58 arranged in circumferentially spaced
apart relationship and retained in position by a ring 60 connected
to the radially outermost portion thereof. The ring 60 is defined
by flat links 62 connected at opposite ends by rivets 64 to a pair
of space apart flat links 66 and 68 each of which are provided with
a notch or recess 70 therein. The links 62 are connected to the
links 66 and 68 in end-to-end fashion to thereby define continuous
ring 60.
The segments 58 each include a core or block of carbon material 72
having a counter sunk opening 74 therethrough between opposite
parallel flat surfaces thereof. A cup or lining button 76 having
the general outline of the carbon block 72 and provided with spaced
apart ears or lug portions 78 and 80 is adapted to retain a layer
of sintered friction material 82 which may take any one of various
known forms. Reference is made to commonly assigned U. S. Pat. No.
3,269,489 issued Aug. 30, 1966 to Douglas Roth and U. S. Pat. No.
2,784,105 issued Mar. 5, 1957 to Frances Stedman and Robert Pocock
for examples of such cup 76 and friction material combination. A
central opening 84 in the layer of friction material 82 and a
dimpled opening 86 in cup 76 are aligned with counter sunk opening
74 in block 72 to permit fastening of a cup 76 to each of the flat
surfaces of block 72 by a rivet 88 suitably upset to fixedly secure
the same together. The ears 78 and 80 have openings 90 therein to
permit fastening of the cups 76 and carbon block 72 secured thereto
the outer ring 60 by rivets 92 which also pass through openings 94,
96 and 98 in links 66, 62 and 68, respectively. It will be noted
that the ear 78 is attached to links 66, 62 and 68 between
associated rivet 64 and notch 70 and the ear 80 is similarly
attached to the adjacent set of links 66 and 68 at the opposite end
of link 62 thereby defining a rigid arcuate section of rotor 52.
The segments 58 defined above are attached in relatively closely
spaced apart relationship to outer ring 60 resulting in structural
rigidity of rotor 52 as well as substantially continuous annular
faces of friction material 82 on opposite sides of the rotor
52.
The stators 54 may take the form of an annular steel ring 100
having suitably radially inwardly extending projections 102
slidably carried for axial movement by sleeve portion 36. The
opposite sides of each stator 54 are provided with a continuous
facing of friction material 82 suitably secured thereto as by
brazing. It will be recognized that the stators 54 are not limited
to the above-described structure but, like rotors 52, may be
constructed with a carbon core to increase the heat sink capacity
of the disc brake or, if desired, only the stator may be provided
with a carbon core in which case the rotor 52 may be formed of
steel or other suitable conventional material. However, in any
event, it will be recognized that carbon is characteristically weak
in strength under stress except for compression such that, as in
the case of the above-described rotor 52, the force derived from a
brake application and imposed on the rotor 52 as well as the stator
54 should be imposed on the carbon material in the form of
compression only if premature deterioration and/or failure of the
brake is to be avoided.
Assuming a brake application is underway, the pistons 26 are
pressurized causing the pressure plate 32 to move axially and
compress the interleaved rotors 52 and stators 54 between pressure
plate 32 and backing plate 38 to create frictional resistance to
rotation of the wheel 20. The energy thus generated is dissipated
in the form of heat which must be absorbed by the brake assembly
including the rotors 52 and stators 54 in particular. The brake
temperatures attained during hard brake applications of heavy
aircraft can become severe causing warping or buckling of the
rotors 52 as well as stators 54, which, in turn, reduces the
effectiveness of the brake and may result in brake
malfunctioning.
In applicant's brake the heat generated is transmitted to the
carbon blocks 72 which exhibits excellent heat capacity as well as
thermal conductivity characteristics and can withstand temperatures
in excess of that which steel or other metals normally used for
rotors and/or stators can tolerate without failure. The quantity of
heat absorbed by the carbon blocks 72 acting as heat sinks tends to
reduce the heat burden imposed on the critical steel or other metal
portions of the rotors and stators which, in turn, reduces the
operating temperatures thereof.
It will be noted that the carbon blocks 72 are subject to
compression by virtue of the position of the same between the
friction cups or lining buttons 76. The torque load transmitted
between the brake rotors 52 and the wheel 20 is carried by the ears
or lugs 78 and 80 of the rotor segments 58 to the exclusion of
carbon blocks 72. The ring 60 is characterized by the links 62, 66
and 68 connected by rivets 64 to minimize the volume of steel
required thereby reducing weight of the rotor 52 accordingly with
no adverse effect on the strength characteristics required of the
rotor 52.
While the carbon material proposed for use in carbon blocks 72 is
preferably conventional non-structural carbon, it is suggested that
other known forms of carbon such as structural carbon, graphite,
etc. may be suitable for use in forming applicant's blocks 72.
* * * * *